Problem: If $x \oslash y = x^{2}+3y^{2}$ and $x \bigtriangleup y = 4x-4$, find $3 \bigtriangleup (-2 \oslash 6)$.
Explanation: We don't need to find $-2 \oslash 6$ because $x \bigtriangleup y$ depends only on the left operand. Find $3 \bigtriangleup y$ $ 3 \bigtriangleup y = (4)(3)-4$ $ \hphantom{3 \bigtriangleup y} = 8$.